Floating seat butterfly valve

Claim 1

A butterfly valve assembly adapted for positioning between opposing, spaced-apart flanges in a fluid flow system, said assembly comprising: A. a rigid body having opposing external flat parallel end surfaces adapted to mate with the opposing flanges, said body having opposing internal end surfaces spaced inwards from and having a smaller diameter than said external end surfaces, said body adapted to permit fluid flow therethrough and to accept a valve closure member; B. a valve closure member rotatably mounted within said body and adapted to cooperate with a seat assembly to regulate fluid flow through said rigid body; C. a seat assembly adapted to co-operate with said valve closure member between an open position and a closed position, said seat assembly comprising: i. a flexible steel ring disposed in said rigid body for resilient flexible engagement with an annular seat; and, ii. an annular seat disposed in said rigid body (supporting said flexible ring), said annular seat is an elastomeric material bonded to and about said flexible ring, said seat assembly and said rigid body defining an annular space therebetween adapted for the passage of a fluid medium therethrough, said seat assembly having an external flange on each end adapted to be clamped between its respective internal end surface and one of the opposing flanges, said external flange on each end extending completely about the flexible steel ring thereby forming a seat for said flexible ring of U-shaped half cross-section configuration; and, D. an inlet connector and an outlet connector communicating with the annular space and adapted to receive and pass a fluid medium therethrough, whereby rotation of said valve closure member to a closed position forces said seat assembly to deform into the annual space and simultaneously permits fluid to pass from said inlet connector through the annular space to said outlet connector.